Synthetic rubberlike material from 1-cyanobutadiene-1,3 and butadienes-1,3



Patented May 26, 1942 OFFICE",

1 CYANOBUTADIENE 1,3 -AND BUTADL.

Bernard James Habgood, Elias Isaacs, and Leslie Budworth Morgan, Blackley, Manchester, England, assignors to Imperial Chemical-Industries Limited, a corporation of Great Britain No- Drawing. Application September 20, 1939,

In Great Britain Septem- Serial No. 295,839. ber 22, 1938 V g 11 Claims.

This invention relates to improvements in the manufacture and application of newsynthetic rubber-like materials.

' an emulsifying agent, are emulsified by agitating According to the invention we manufacture synthetic rubber-like materials by interpolymerising in aqueous emulsion a mixture of butadiene-l:3 or a homologue ofrbutadiene-lz3 and 1-cyanobutadiene-1r3, the mixture containing a minor proportion of the latter; Also according to theinvention we vulcanise polymerizedproducts obtained by the above process by subjecting them to a heat treatment in the presence of compounding ingredients.

ation if the ingredients of the mixture, including at the temperature atwhich polymerisation is to be: effected and agitation then continued long enough for the'necessary polymerisation, to-take place. Suitable emulsifyingagents are cetyltri methyl-ammonium bromide; jcetyl p-dimetliyl- V aminobenzoate, methosulphate, sodium cetyl Y sulpha'te, sodium isopropylnaphthalene sulphonate, and other salts,,deri ved from long chainbases andinorgan ic or organic acids or from organic acids. of high" molecular weight and inorganic By the inclusionof the l-cyanobutadiene-lz3i synthetic rubber-like materials are obtained,

which after vulcanisation have much greater resistance to oils and solvents than the corresponding materials obtained from the; polymerstyrene. esters of acrylic acid and many other isation of butadiene-l:3 itself or. its homologues. or from the interpolymerisation of these with substances which have been recommended. This resistance to oils and solvents is of the greatest importance in synthetic rubber-like materials.

' because it is this resistance which provides them with their most importantadvantage over natural rubber. In addition to this highiresistance to oils and solvents,.the syntheticjrubber-like materials of this invention are excellent in other respects such as elasticity, tensile strength, re-

sistance to abrasion, resilience and ease of working. Further, the process of the invention takes place readily and gives good yields of the rubberlike products. a

This invention does not exclude the use of minor proportions of other polymerisable substances, for example substances which are known to polymerise with butadiene-lzii, such as styrene, methyl methacrylate and acylonitrile. By

minor proportions we mean proportions smaller than those of the butadiene-1:3 or its homologues or of the l-cyanobutadiene-lzB. The proportions in which the substances to be polymerised are to beused will depend upon the proportions required in the resulting products, especially upon the degree of resistance to oils and solvents which is required. A useful improvement in resistance can be obtained with as low a proportion of l-cyanobutadiene-1z3 as 5%,.1. e.

5% of 1-cyanobutadiene-123 and 95% of butadiene-1:3. For a high degree of resistance, proportions of -40% of 1-cyanobutadiene-1z3 can be used.

The emulsification and polymerisation can be conveniently effected in a single technical operheat treatment.

bases. Smallproportions ofpn'e or more electrolytes e. g. acetic acid or acetic acid admixed with.

sodium acetate may be included in the polymerisation mixtures Other ingredients may be included injthe mixture, namely, agentsiwhich are known to catalyse polymerisation such as organic ;and inorganic peroxides and agents which modify the course of the polymerisation such ascarbon tetrachloride. The. products of polymerisation are produced inglatex-like form. Theymay be obtained in massive form by coagulatingtth'e latex,- removing the liquor and washingand-drying the coagulum. The coagulation may be effected by known methods e. g. byfreezing or by the addition of sodium chloride, sodium hydrox-- ide or ethyl alcohol, depending upon the emulsifying agent, which-has been employed. Washing and drying may be-efl'ected on a rubber roller mill which is fitted with a device for washing.

- The dry rubber-like materials may be compounded with for example, filling and/or reinforcing ingredients such as carbon black'a'nd zinc oxide and/or-vulc'anising agents, for example sulphur and vulcani'sation accelerators. "The compounded material, may then.

The following e'xamples,in which parts are by weight, illustrate but do not limit the invention.

Example 1 parts of 1-cyanobutadiene-1:3, parts of butacliene-lz3, 5 parts of carbon tetrachloride,

400 parts of water, 4 parts of cetyl p-dimethylaminobenzoate methosulphate and .22 parts of 6% acetic acid are enclosed in an autoclave and agitated for five days at C. The resulting latex is coagulated by adding parts of 8% aqueous sodium hydroxide solution and'warming to about 40 C. The coagulum is washedand.

dried on a rubber-roller mill; A rubber-like material is obtained. 7

be vulca'nised by a I tool-parts "oi;

- similar circumstancesfoi 56%} 2. Process fcr the m y thetic rubber-like materi als .which comprises polymerizing, in aqueouswemulsiom. l-cyanobulatter material beingpresent Example 2 'rne rubber-like material obtained in' Emmple 1 is included in the following mixing:

I Parts The ,mix is vulcanisedi'oronehour 1415c;

A vulcanisate is obtained which has amaximum 2,2s4,2s1"' H a Y,

3. Process, tor the manufacture of new mi-1"" 'tensilestrength' or about 200 n. cm.= andan elongation at break or 400%. ,;-It does not swell, when immersed in hotmineraloils and. swells to less than,190% of its original volume when immersed in benzene. i

I ,Ezample 3 e'mulsiilcatiohv and polyinerisation conditionsde "s cribfed in Example v1"and;theQres'ulting latex 1,3;

coa'sfu ated andlth' dg m washed d dri sinmm le 1; a

a good rubberelike mfitenaris'ontam a;

. ,Isopr'ene, or a 2 iST-diphethyIbutadiene- I 31 may missed, instead oi butadiene lfi m the above a 11mm j i'i ne rubber likematerial ol n 1 1 pounded and-:vulcanised in-Exam le 2w g V The v'ulcanisate," ontesting; shows a maximum; tensile strength of "273' kg./cms., and} when 1 im-'-? mersed in Diesel'oil for 7 days at 70 C. showed 1 aswelling" oi only-9% oi the original volume. A similar ivulcanisate obtained irom polymerised z chlorobutadiene-l :3; showed a swelling under 7 1.,Process1or the; manuiacturerof new synthetic rubber-like; materials which ecomprises polymerizing, in aqueous emulsion,zll-cyanobutadiene-l,3.together -with a member of the group consisting of butadiene-1,3 zmethylbutadiene- 1,3," and 2,3-dimethylbutadiene -L3, the latter material being presentin -larger amounts than' the former'material. H; i V H uiacture or. newsyntadiene-IB" together with butadiene-1,3, the

than the iormermaterial,"

I 7 water, lfi parts or cetyl-pfdimethyl-aminobenzoate,methosulphate, 22 parts of 6% acetic acid, parts oil-carbon tetrachloride, 25 ermit: lcyanobutadiene-lzii 50 parts of butadiene l:3 .,are'subjected to; the w manner described a 40 a polymerization product of a mixture of from "5 percent to. 40 per centl-cyanobutadiene-ls "and from 95 percent tot!) per cent- -butadienethetic rubber-like materials which comprises polymerizing,.-in aqueous emulsion, 'a mixture comprising irom.5 per cent to 40 per cent l-cycentbutadiene-1, 3. a

anobutadiene-1,3 andirom 95 per; cent to 60 per 4. Process for the manuiactureor new synthetic rubber-likev materials which comprises polymerizing, in aqueous emulsion, a mixture comprising from 20 per cent to 40 per oentil-cyanobutadiene:1, 3f and from cent butadiene-l,3.

5. 4 synthetic rubber-like material comprising a" pclymerization' product of a mixture or l-cyanobutadiene-IJ and a member of the group consisting "of butadiene-1,3, 2-methylbutadi'ene- 51,3 2,3-dimethylbutadiene-L3, the latter material beingvpresent in larger amounts than the iormer;material;

3 6. .,A synthetic rubber-like material comprising '7. A synthetic, rubberrlike material comprising .-a polymerizatiomproduct-ot a mixture of: from 20 per "cent to" 40. per; cent l-cyanobutadiene-l;

and from aoiperlicentfiq perlcent butadiene- ,a. Process mime mammar -seam thetic, rubber-like materials "which polymerizing. in aqueous-emulsion; akmixture or w from-5 percent to 40' percent" l-cyanobutadime- 1,3 and from 95;per cent to '801per' cent'o! a member- 20i. the"'g'roup consisting of butadiene- 1,3, ;2-methylbutadiene-1;3 and 2,3-diniethylbutadiexie-lfl, compounding and curing ber-likemater'ial thus obtained," a 9; Process tor the manuiactur'e oi new syn-m thetic rubber-like: materials which comprises polymerizing in'aqueous emulsion/a mixture of from 2i) :per' cent to 40 per cent, 1 l-"cyanohutadiene-1-,3 and*irom "80per 'cent to 69 per cent butadiene-1,3," wmpounding' 'and curing rub 4 1,; I

ber -likemat'erialthus obtained.

- =10. Cured synthetid mum-1m mm wherein the rubber-like ingredient is" a} 901;- merizationproduct 0t ofjfrom =5 "per 'cent to'io 'per cent 'l-cyanobu'tadiene-LS and inlarger amounts 9 irom195 per *cent'to per centbutadiene-m:

V Y 11." synthetic rubber-like wherein the rubber-likednsredient is a' poly- 'merlzation product or a 'ot-Irom 2019c! gfcent' to'40 per "l-cyanobutadiene-lfi and from per cent per cent butadiene-LS;

80 per cent to 60 per 

